title: (+)-Geodin from Aspergillus terreus.
abstract: The fungal metabolite (+)-geodin [systematic name: (2R)-methyl 5,7-dichloro-4-hydroxy-6'-methoxy-6-methyl-3,4'-dioxospiro[benzofuran-2,1'-cyclohexa-2',5'-diene]-2'-carboxylate], C(17)H(12)Cl(2)O(7), was isolated from Aspergillus terreus. The crystal structure contains two independent molecules in the asymmetric unit. Molecules denoted 1 interact through O-H...O hydrogen bonds creating chains of molecules parallel to the crystallographic 2(1) screw axis. Molecules denoted 2 interact through an O...Cl halogen bond, also creating chains of molecules parallel to the crystallographic 2(1) screw axis. Molecules 1 and 2 interact through another O...Cl halogen bond. The two molecules are similar but molecules 2 have a slightly more planar cyclohexadiene ring than molecules 1. The absolute structure of (+)-geodin has been unequivocally assigned with the spiro centre having the R configuration in both molecules. The structurally related (+)-griseofulvin has an S configuration at the spiro centre, a difference of potential biological and biosynthetic relevance.
authors.affiliation: Department of Chemistry, Technical University of Denmark, Kgs. Lyngby, Denmark.
authors.forename: Mads H
authors.initials: MH
authors.lastname: Rønnest
authors.forename: Morten T
authors.initials: MT
authors.lastname: Nielsen
authors.forename: Blanka
authors.initials: B
authors.lastname: Leber
authors.forename: Uffe H
authors.initials: UH
authors.lastname: Mortensen
authors.forename: Alwin
authors.initials: A
authors.lastname: Krämer
authors.forename: Mads H
authors.initials: MH
authors.lastname: Clausen
authors.forename: Thomas O
authors.initials: TO
authors.lastname: Larsen
authors.forename: Pernille
authors.initials: P
authors.lastname: Harris
mesh_terms: D001230:Aspergillus / Q000737:chemistry; D001572:Benzofurans / Q000737:chemistry* / Q000302:isolation & purification; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D001572:Benzofurans; C052047:geodin